1. Field of the Invention
This invention relates to a swing resistance regulating device capable of steplessly regulating swing resistance in a swing braking device of a tripod head or panhead of a video camera, a motion picture camera or the like.
2. Brief Description of the Prior Art
Heretofore, a panhead of, for example, a video camera, is mounted on a tripod and a camera is fixed onto the panhead, so that the fixed camera can be paned and/or tilted. It is more preferable for a device for taking a motion picture such as video camera, that a camera is paned or tilted under a certain size of resistance rather than under no resistance. Therefore, it is usually equipped with a device for regulating resistance. It is also preferable for such device that the size of resistance can be freely adjusted or regulated depending on the angle of view, the weight of a camera, or personal preference of a camera man. Furthermore, this resistance must be a viscous resistance instead of a friction resistance.
The friction resistance is heavy at start and becomes light during swinging motion. It tends to become unstable during pacing operation. On the other hand, the viscous resistance is light at start and becomes heavier and the swinging speed is increased. Therefore, there can be obtained a stable swinging speed.
A conventional swing resistance regulating device, as shown in FIG. 5, is designed such that a brake mechanism 2 is disposed along the inner periphery of a cylindrical back plate 1, one ends of a pair of half-circular shoe members 3, 3 of this brake mechanism being rotatably mounted by pins 4, the other ends 5, 5 being spaced apart, a control member 6 having a tapered surface being slideably contacted therewith, the distance between the right and left shoe members 3, 3 being widened by the tapered surface. With the construction mentioned, however, the friction resistance is increased and thus undersirable. If fats and oils are applied onto the contact surface of the shoe members 3, 3 with respect to a back plate in order to reduce the friction resistance, the resistance is reduced and therefore a desired size of resistance is unobtainable. If it is pressed hard in order to increase the resistance, the oil film is cut and a point contact is taken place, thus becoming a friction resistance.